What does the metrics SPI, CPI, IETS stand for ?

It seems thar some field descriptions are missing from the page. I will follow up on that. 
Here are some field descriptions that may be useful:

 

SPI
Schedule Performance Index, calculated as Earned Value divided by the Budgeted Cost for Work Scheduled, BCWP/BCWS. It indicates if the progress is ahead of or behind schedule. A value of one (1) indicates that the work performed is in accordance with the work scheduled to be performed. A value greater than 1 indicates that work performed is ahead of schedule, and a value less than 1 indicates that work performed is behind schedule. This field is calculated and cannot be modified. Value on the sum line is using the summarized values for the entire selection in the calculation. It is not a simple sum of the column.

CPI
Cost Performance Index, calculated as the Earned Value divided by the Actual Cost of Work Performed, BCWP/ACWP. It indicates if the budgeted cost for the work performed is more or less than the actual cost for work performed.  A value of one (1) indicates that the cost for work performed is in accordance with the budgeted cost for this work. A value greater than 1 indicates that the cost for work performed is less than the budgeted cost for this work. A value less than 1 indicates that the cost for work performed is more than the budgeted cost for this work. Better information on the project's performance can be obtained by studying the Cost Performance Index instead of only the Cost Variance. Consider the following example:

Activity          BCWP           ACWP          CV          CPI
Activity 1        200,000          220,000        -20,000     0.9
Activity 2         50,000            70,000        -20,000      0.7

Both activities have the same CV, but the CPI clearly shows that activity 2 has a far greater problem than activity 1. This could not be detected by only looking at the Cost Variance. This field is calculated and cannot be modified. Value on the sum line is using the summarized values for the entire selection in the calculation. It is not a simple sum of the column.

ETC
Estimate to Complete is the total estimated remaining cost to complete the activity. The field cannot be modified. The estimated remaining cost to complete the activity for each cost element is changed in Project Navigator/Activity/Estimate.

EAC
The Estimate At Completion. This value is equal to the Actual Cost of Work Performed plus the Estimate To Complete (ACWP+ETC). This field is calculated and cannot be modified.

VAC
The Variance At Completion, calculated as the Budget At Completion minus the Estimate at Completion (BAC-EAC). A negative value indicates that the given estimate to complete will result in that the costs at completion will exceed the budget. This field is calculated and cannot be modified.

CV
The Cost Variance, calculated as the Earned Value minus the Actual Cost of Work Performed (BCWP - ACWP). It indicates whether costs to date are better or worse than budgeted for the work performed. A positive value indicates that costs to date are less than budgeted for the work performed. A negative value indicates that costs to date are more than budgeted for the work performed. This field is calculated and cannot be modified.

SV
The Schedule Variance, calculated as the Earned Value minus the Budgeted Cost for Work Scheduled (BCWP - BCWS). It indicates whether costs to date are ahead of or behind schedule. A positive value indicates that costs to date are ahead of schedule. A negative value indicates that costs to date are behind schedule. This field is calculated and cannot be modified.

IETC
The Independent Estimate To Complete, calculated as the Budget at Completion minus the Earned Value, divided by the Cost Performance Index, or (BAC-BCWP)/CPI. It is an estimate of the cost required for completion, based on work continuing at the current rate of earned value. This field is calculated and cannot be modified. Value on the sum line is using the summarized values for the entire selection in the calculation. It is not a simple sum of the column.

IEAC
The Independent Estimate At Completion, calculated as the Actual Cost of Work Performed plus the Independent Estimate To Complete (ACWP + IETC). It is the final cost if the rate of spending remains the same. It is an estimate of the revised cost at completion based on the work continuing at the current rates of Earned Value and actual costs. This field is calculated and cannot be modified. Value on the sum line is using the summarized values for the entire selection in the calculation. It is not a simple sum of the column.

IVAC
The Independent Variance At Completion, calculated as the Budget At Completion minus the Independent Estimate At Completion (BAC-IEAC). It is a cost estimate of how the budget will be affected if there is no change to the current rate of Earned Value and the current rate of used costs. A negative value indicates that the current rate of Earned Value and used costs will result in that the costs at completion will exceed the budget. This field is calculated and cannot be modified. Value on the sum line is using the summarized values for the entire selection in the calculation. It is not a simple sum of the column.